ADP Bonus Tax Rate: Flat 22%, Aggregate Method, and FICA

When ADP runs a bonus through payroll, federal income tax is usually withheld at a flat 22%, but the actual ADP bonus tax rate on your stub depends on which method your employer selected: the flat supplemental rate or the aggregate method, which combines the bonus with your regular wages and often produces a higher percentage. Social Security, Medicare, and state income tax come out on top of whichever federal rate applies, so total withholding on a bonus typically lands between 30% and 40% of the gross amount.

The Two Methods ADP Can Apply

The IRS allows employers two ways to withhold federal income tax on bonuses and other supplemental wages, which include commissions, severance, back pay, and overtime.¹ Your employer picks the method, not you, and ADP’s platform supports both.

Flat 22% Rate

The simpler option withholds exactly 22% of the bonus for federal income tax, regardless of what’s on your W-4. A $5,000 bonus produces $1,100 in federal withholding, with no adjustment for dependents, extra withholding requests, or filing status. The flat rate is only available when your employer identifies the bonus separately from regular wages in payroll records. If the two are lumped into one undifferentiated paycheck, the entire payment has to be treated as ordinary wages.¹

Aggregate Method

The aggregate method combines your bonus with your regular wages for the same pay period and calculates withholding on the combined total as if it were a single regular paycheck, using the standard IRS withholding tables and your W-4 elections. The tax already scheduled to come out of your regular wages is subtracted, and the remainder is withheld from the bonus.¹

In many ADP configurations, the aggregate method is the default. The flat 22% rate requires the payroll administrator to make an active selection on the supplemental pay screen; without that selection, the system falls back to aggregate.² That default is the single most common reason employees see federal withholding on a bonus that doesn’t match the 22% they expected.

Why the Aggregate Method Often Withholds More

The aggregate calculation annualizes the combined paycheck. It essentially asks: if this person earned this much every pay period, what bracket would they land in? A $10,000 bonus added to a $4,000 biweekly paycheck makes the system treat you as earning $14,000 every two weeks, or $364,000 a year. The withholding is calculated against the brackets that income would produce, often 32% or 35%, even when your actual annual income is nowhere near that level.

The method can also work in the opposite direction. If your regular pay plus the bonus still falls in the 10% or 12% bracket on an annualized basis, the effective withholding on the bonus can come out below 22%. If your bonus stub shows federal withholding noticeably above or below 22%, the aggregate method was almost certainly used. Your payroll department can confirm which method they chose, and the choice can vary from one bonus run to the next.

FICA and State Tax Come Out on Top

Whichever federal income tax method applies, bonuses are also subject to the same Social Security and Medicare taxes that hit every regular paycheck.¹

Social Security: 6.2% on earnings up to $184,500 in 2026. If your year-to-date wages have already crossed that cap, no Social Security tax comes out of the bonus.³
Medicare: 1.45% on all earnings with no cap.⁴
Additional Medicare Tax: an extra 0.9% once your year-to-date wages exceed $200,000. Your employer must start withholding it at that point regardless of your filing status.⁵

For someone below the Social Security cap, FICA alone takes 7.65% of the bonus. Stack that on the 22% flat federal rate and you’re at 29.65% before state tax enters the picture.

Most states with an income tax also withhold on bonuses. Some set a flat supplemental rate (anywhere from roughly 3% to over 13%), others require employers to use the regular wage tables, and a handful of states have no income tax at all. ADP applies the correct state supplemental rate automatically based on your work location. Between federal income tax, FICA, and state tax, total withholding on a bonus commonly lands in the 30–40% range, and higher in high-tax states once Social Security tops out.

Bonuses Over $1 Million

A separate mandatory rate kicks in once your total supplemental wages from one employer exceed $1 million in a calendar year. Every dollar above that threshold is withheld at 37%, the top individual income tax rate, and the employer has no discretion to use a different method.¹ The first $1 million can still use the flat 22% or aggregate method; the excess is locked at 37%. The rate was permanently set when Congress extended the individual tax rate structure through P.L. 119-21 in 2025.⁶ For most employees this threshold is irrelevant, but if you receive large commissions, signing bonuses, or equity-based pay, ADP tracks the running total and switches rates automatically once you cross the line.

What’s Withheld Is Not What You Owe

Whatever ADP takes out of your bonus is a prepayment toward your annual tax bill. Your real liability gets settled when you file Form 1040, which looks at your total income, deductions, and credits for the year.⁷

The flat 22% rate is a blunt instrument. If your taxable income puts you in the 12% bracket, the 22% withheld on the bonus was too high and you’ll get the difference back as a refund. If your income puts you in the 32% or 35% bracket, 22% wasn’t enough and you’ll owe the shortfall when you file. The aggregate method tends to over-withhold on large bonuses because of the annualization effect. Either way, filing reconciles it.

What You Can Do About Bonus Withholding

You can’t choose the method your employer uses, but you can shape the yearly outcome.

Form W-4 line 4(c) lets you request an additional flat dollar amount of federal withholding per pay period, and your employer must honor a request for increased withholding.⁸⁹ If you know a bonus is coming and your normal withholding is already running short, bumping up line 4(c) before the bonus pay period adds extra. Submit a new W-4 afterward to bring withholding back to its usual level, or you’ll keep overpaying on every paycheck that follows.

If a bonus caused significant over-withholding and you’d rather not wait for a refund, you can reduce your regular withholding for the remainder of the year. Adjusting your deductions estimate on a new W-4 lowers tax taken from each remaining paycheck and offsets the excess that came out of the bonus. Neither move changes the bonus withholding itself. Both move your year-end position closer to break-even.

When the Employer Promises a Net Bonus Amount

Some employers quote a bonus as a specific after-tax figure, say $5,000 net. Delivering that requires “grossing up” the payment so withholding leaves exactly $5,000 in your hand. Using the flat method, the formula is:

Gross bonus = Desired net ÷ (1 − combined tax rate)

Combined rate stacks federal (22%), Social Security (6.2%), and Medicare (1.45%) for 29.65%. To net $5,000:

$5,000 ÷ 0.7035 = $7,109.45

State income tax, where applicable, has to be added to the combined rate before running the calculation. ADP’s paycheck calculator will back-solve the gross figure from the desired net.² If you were promised a net amount and the math on your stub doesn’t match, ask whether the gross-up accounted for state and local taxes.

Year-End Bonus Timing

If a bonus hits near the end of December, the tax year it counts in depends on when the funds are actually available to you, not when payroll decides to pay it. Income is taxable in the year it’s made available. A direct deposit landing December 31 is that year’s income. A check your employer holds until January 2 belongs to the following year. One exception: if the employer credits the bonus to your account but restricts your ability to withdraw it until a later date, the credit alone isn’t income. The bonus becomes taxable in the year the restriction lifts.¹⁰

1
Internal Revenue Service. Publication 15 (2026), (Circular E), Employer’s Tax Guide – Section: 7. Supplemental Wages
2
ADP. EasyPayNet Bonus Payrolls
3
Social Security Administration. Contribution and Benefit Base
4
Social Security Administration. 2026 Cost-of-Living Adjustment (COLA) Fact Sheet
5
Internal Revenue Service. Topic No. 560, Additional Medicare Tax
6
GovInfo. Public Law 119-21
7
Internal Revenue Service. About Form 1040, U.S. Individual Income Tax Return
8
Internal Revenue Service. Form W-4, Employee’s Withholding Certificate
9
Internal Revenue Service. Withholding Compliance Questions and Answers
10
eCFR. 26 CFR 1.451-2 – Constructive Receipt of Income